x86/string.s

   1 format ELF
   2
   3 public memcpy
   4 memcpy:
   5         push    esi
   6         push    edi
   7         mov     edi, [esp+12]
   8         mov     esi, [esp+16]
   9         mov     ecx, [esp+20]
  10         mov     eax, edi
  11         cld
  12         rep movsb
  13         pop     edi
  14         pop     esi
  15         ret
  16
  17 public memmove
  18 memmove:
  19         push    esi
  20         push    edi
  21         mov     edi, [esp+12]
  22         mov     esi, [esp+16]
  23         mov     ecx, [esp+20]
  24         cmp     edi, esi
  25         jng     .usual
  26         mov     eax, esi
  27         add     eax, ecx
  28         cmp     edi, eax
  29         jg      .usual
  30
  31         mov     eax, edi
  32         std
  33         add     esi, ecx
  34         add     edi, ecx
  35         dec     esi
  36         dec     edi
  37         rep movsb
  38         jmp     .ret
  39 .usual:
  40         mov     eax, edi
  41         cld
  42         rep movsb
  43 .ret:
  44         pop     edi
  45         pop     esi
  46         ret
  47
  48 public memset
  49 memset:
  50         push    edi
  51         mov     edi, [esp+8]
  52         mov     eax, [esp+12]
  53         mov     ecx, [esp+16]
  54         mov     edx, edi
  55         cld
  56         rep stosb
  57         pop     edi
  58         mov     eax, edx
  59         ret
  60
  61 public memchr
  62 memchr:
  63         mov     eax, [esp+8]
  64         mov     ecx, [esp+12]
  65         push    edi
  66         mov     edi, [esp+8]
  67         test    ecx, ecx
  68         jz      .failed
  69         cld
  70         repnz scasb
  71         jne     .failed
  72         mov     eax, edi
  73         dec     eax
  74         jmp     .ret
  75 .failed:
  76         xor     eax, eax
  77 .ret:
  78         pop     edi
  79         ret
  80
  81 public memcmp
  82 memcmp:
  83         push    esi
  84         push    edi
  85         xor     eax, eax
  86         mov     esi, [esp+12]
  87         mov     edi, [esp+16]
  88         mov     ecx, [esp+20]
  89         jecxz   .ret
  90
  91         cld
  92         rep cmpsb
  93         jz      .ret
  94         sbb     eax, eax
  95         or      eax, 1
  96 .ret:
  97         pop     edi
  98         pop     esi
  99         ret
 100
 101 public strlen
 102 strlen:
 103         push    edi
 104         mov     edi, [esp+8]
 105         xor     eax, eax
 106         mov     ecx, -1
 107         cld
 108         repnz scasb
 109         mov     eax, ecx
 110         not     eax
 111         dec     eax
 112         pop     edi
 113         ret
 114
 115 public memrchr
 116 memrchr:
 117         mov     eax, [esp+8]
 118         mov     ecx, [esp+12]
 119         push    edi
 120         mov     edi, [esp+8]
 121         add     edi, ecx
 122         dec     edi
 123         test    ecx, ecx
 124         jz      .failed
 125         std
 126         repnz scasb
 127         jne     .failed
 128         mov     eax, edi
 129         inc     eax
 130         jmp     .ret
 131 .failed:
 132         xor     eax, eax
 133 .ret:
 134         pop     edi
 135         ret
 136
 137 public strchr
 138 strchr:
 139         mov     ecx, [esp+4]
 140         mov     edx, [esp+8]
 141 .loop:
 142         mov     al, [ecx]
 143         cmp     al, dl
 144         jz      .done
 145         inc     ecx
 146         test    al, al
 147         jnz     .loop
 148         xor     ecx, ecx
 149 .done:
 150         mov     eax, ecx
 151         ret
 152
 153 public strcmp
 154 strcmp:
 155         mov     ecx, [esp+4]
 156         mov     edx, [esp+8]
 157         xor     eax, eax
 158 .loop:
 159         mov     al, [ecx]
 160         cmp     al, [edx]
 161         jnz     .ret
 162         inc     edx
 163         inc     ecx
 164         test    al, al
 165         jnz     .loop
 166         ret
 167 .ret:
 168         movzx   ecx, byte [edx]
 169         sub     eax, ecx
 170         ret
 171
 172 public strcpy
 173 strcpy:
 174         push    edi
 175         push    esi
 176         mov     edx, [esp+12]
 177         mov     esi, [esp+16]
 178         mov     edi, edx
 179         cld
 180 .loop:
 181         lodsb
 182         stosb
 183         or      al, al
 184         jnz     .loop
 185         pop     esi
 186         pop     edi
 187         mov     eax, edx
 188         ret
 189
 190 public strrchr
 191 strrchr:
 192         push    edi
 193         mov     edi, [esp+8]
 194         mov     ecx, [esp+12]
 195         xor     edx, edx
 196         dec     edi
 197 .loop:
 198         inc     edi
 199         mov     al, [edi]
 200         test    al, al
 201         jz      .done
 202         cmp     al, cl
 203         jnz     .loop
 204         mov     edx, edi
 205         jmp     .loop
 206 .done:
 207         mov     eax, edx
 208         pop     edi
 209         ret
 210
 211 public strncmp
 212 strncmp:
 213         mov     ecx, [esp+4]
 214         mov     edx, [esp+8]
 215         xor     eax, eax
 216         push    edi
 217         mov     edi, [esp+16]
 218 .loop:
 219         test    edi, edi
 220         jz      .failed
 221         mov     al, [ecx]
 222         cmp     al, [edx]
 223         jnz     .ret
 224         inc     edx
 225         inc     ecx
 226         dec     edi
 227         test    al, al
 228         jnz     .loop
 229 .failed:
 230         xor     eax, eax
 231         pop     edi
 232         ret
 233 .ret:
 234         movzx   ecx, byte [edx]
 235         sub     eax, ecx
 236         pop     edi
 237         ret